The verification code is printed on the Notice of Rejection.
The timeline here makes no sense, it normally takes several months to get get a hearing at London Tribunals, you first post was on 8 January but the tribunal decision was promulgated on 31 January, yet I can't see any evidence that you ever posted a formal Notice of Rejection on here. You must have got one at some point because you managed to appeal to London Tribunals (though for some bizarre reason it seems you did this with a paper form rather than via the online portal), but if you never showed us the formal Notice of Rejection we wouldn't have known you were at the tribunal stage so we obviously couldn't advise you on how to go about it.
I suspect you'd already appealed to the tribunal before you made your first post, but it's hard to tell as you've deleted all the documents.